The invention relates to a wheel for a motor vehicle having a rim spider with air openings and a rim well connected with the rim spider. More particularly, the wheel includes at least two shell parts constructed as a rim well and a rim spider which each have a shaped-out interior and exterior wall which are connected with one another. The shell parts define radially extending hollow spokes and a radially outer annulus and a radially inner annulus between meeting wall areas of adjacent air openings of the shell parts. Receiving devices for mounting bolts are provided between adjacent air openings of the wheel in the area of the wheel hub.
From U.S. Pat. No. 4,610,482, a vehicle wheel is known which has a rim spider which is connected with a rim well by means of a weld, air openings, and mounting bores situated partially opposite the air openings.
In European Patent Document EP-A-0 768 191, a vehicle wheel is described which comprises two shell parts which form hollow spokes in the connected condition. The receiving devices for the mounting bolts of the wheel are each assigned to one air opening; that is, they are arranged directly below the rounding of the air opening facing the wheel hub so that the air opening surface is bounded by the receiving devices. Furthermore, from German Patent Document DE-U-74 16 695, a vehicle wheel is known which has air openings and these are partially arranged below the air openings close to the wheel center. In addition, from German Patent Document DE-A-44 30 489, a vehicle wheel is known which has hollow spokes and an exterior and interior annulus, between which air openings are arranged.
It is an object of the invention to provide an arrangement of the receiving devices for the mounting bolts in the wheel which, in addition to an increased stability in the wheel hub area, also permits a free design of the air openings.
According to the invention, this object is achieved by arranging the receiving devices on a circle, in a transverse center plane of the hollow spokes, and at a distance from a contact circle with the air openings. The air openings are constructed in an approximately triangular shape with rounded corners, with the rounded corner pointing to the wheel center facing an area between two adjacent receiving devices. The receiving devices are shaped out on the end side of the hollow ribs in the shell part of the rim spider and are connected with the rim sleeve. The rim sleeve is held, fitted in an interior ring of a shaping-out of the interior annulus by the shell part of the rim well and is connected with it.
The principal advantages achieved by the invention are that, as the result of the arrangement of the receiving devices for the mounting bolts of the wheel in an area of the wheel hub between the air openings of the wheel, the sizes of the air openings do not have to be limited. Furthermore, the area in a center plane of the air openings is not weakened by a bore for the wheel mounting bolts.
The wheel hub area of the rim spider shell part is formed by the cylindrically shaped-out receiving device for the mounting bolt with hub sleeves molded on in the interior. These cylindrical receiving devices project into a recessed annulus of the rim well shell part.
For connecting the two shell parts, the hub sleeve is fitted into an interior ring of the recessed annulus.
The recessed annulus is arranged on the end side of the hollow rib or half the hollow rib of the rim well shell part and can therefore easily be produced by a casting or forming process. This also applies to the manufacturing of the rim spider. A hydroforming process can also be used.
In contrast to the air openings according to European Patent Document EP-A-0 768 191, the air openings are provided with a shaped-out rounding which extends to the space between two mountings of the wheel and therefore results in a larger opening surface.
Diecast shells can be used for the shell parts which are preferably connected by means of an electron beam welding process. Other welding processes are also conceivable.
The materials for the shell parts consist of light-metal alloys, such as an aluminum alloy or a magnesium alloy. The two shell parts may consist of the same materials or of different materials, as, for example, of an aluminum alloy and a magnesium alloy.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.